Technical Field
The present invention relates to a shovel having a turning body mounted on a running body, and a control method thereof.
Description of Related Art
In the technical field of construction machines such as a shovel having a turning body that is turnably mounted on a running body, there is known a technique to stop a turning operation of the turning body when an entering object enters a turning range. This kind of shovel stops the turning operation of the turning body by shutting off the supply of operating oil to a turning hydraulic motor.
However, it is difficult for the above-mentioned shovel to stop the turning body immediately after shutting off the supply of operating oil to the turning hydraulic motor due to a moment of inertia. This is because an attachment having a large moment of inertia is attached to the turning body of the shovel, which causes the moment of inertia of the turning body to become large. That is, the large moment of inertia of the attachment causes the turning body to be difficult to make an immediate stop.
Thus, it is desirous to develop a technique to reliably avoid a contact between a shovel and an entering object when the entering object enters a monitoring range of the shovel.